To All,
Just to confirm that I'm not way off base here I'd like to present what I believe are the general guidelines for the placement of ballast tanks and weights. Please feel free to whup me upside the head i*** I'm wrong.
These following two rules apply to a boat where the ballast tank is exposed to the outside water - a wet hull boat:
1) The top of the ballast tank should be at the surfaced water line. This keeps the center of buoyancy high as possible and gives us the most "bang for our buck" in terms of raising the boat to the surfaced water line.
2) The center of gravity/mass should be as low as possible to maximize the distance between the center of buoyancy and the center of gravity. This should maximize the righting moment arm.
In a dry hull boat where ballast tanks are inside the dry hull only rule 2) (above) is important. The center of buoyancy is determined by the shape of the dry hull. I'd guess that even if I was building a dry hull boat I'd try to keep all the "dryness" below the surfaced water line. I'd stuff in extra closed cell foam if I needed to raise it more.
In reality, there's no big difference between a wet or a dry hull boat in that in a wet hull boat the ballast tank's outer skin is the same as the dry hull, the WTC being the dry hull with an outer skin attached to it to give the appearance of a submarine.
Let the whacking begin...
Dan
Just to confirm that I'm not way off base here I'd like to present what I believe are the general guidelines for the placement of ballast tanks and weights. Please feel free to whup me upside the head i*** I'm wrong.
These following two rules apply to a boat where the ballast tank is exposed to the outside water - a wet hull boat:
1) The top of the ballast tank should be at the surfaced water line. This keeps the center of buoyancy high as possible and gives us the most "bang for our buck" in terms of raising the boat to the surfaced water line.
2) The center of gravity/mass should be as low as possible to maximize the distance between the center of buoyancy and the center of gravity. This should maximize the righting moment arm.
In a dry hull boat where ballast tanks are inside the dry hull only rule 2) (above) is important. The center of buoyancy is determined by the shape of the dry hull. I'd guess that even if I was building a dry hull boat I'd try to keep all the "dryness" below the surfaced water line. I'd stuff in extra closed cell foam if I needed to raise it more.
In reality, there's no big difference between a wet or a dry hull boat in that in a wet hull boat the ballast tank's outer skin is the same as the dry hull, the WTC being the dry hull with an outer skin attached to it to give the appearance of a submarine.
Let the whacking begin...
Dan
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